N-face GaN films with hillock-free smooth surfaces grown by group-III-source flow-rate modulation epitaxy. (24th February 2016)

• Record Type: Journal Article
• Authors: Lin, Chia-Hung; Akasaka, Tetsuya; Yamamoto, Hideki
• Is Part Of: Japanese journal of applied physics. Volume 55:Number 4(2016:Apr.)Supplement 4
• Publication Date: 2016-02-24
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.55.04EJ01
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: N-face GaN films were grown by group-III-source flow-rate modulation epitaxy (FME), wherein the flow-rate of group-III sources are sequentially modulated under a constant supply of NH3 . By using GaN bulk substrates with a low misscut angle (∼0.3°), hillock-free N-face GaN surfaces are achieved over almost the whole sample area (10 × 5 mm 2 ). A smooth surface with the root mean square roughness of 0.39 nm exhibits the step-and-terrace structure. Group-III-source FME also reduces carbon impurities in the films, resulting in weakened blue and yellow deep emissions in the photoluminescence spectrum.